<template>
	<view>
		<view class="search-box">
			<my-search @click="gotoSearch"></my-search>
		</view>

		<view class="scroll-view-container">
			<scroll-view :style="{height: wh + 'px'}" class="left-scroll-view" scroll-y="true">
				<block v-for="(item, i) in cateList" :key="i">
					<view @click="activeChanged(i)" :class="['left-scroll-view-item', i === active ? 'active' : '']">
						{{item.cat_name}}
					</view>
				</block>
			</scroll-view>
			<scroll-view :scroll-top="scrollTop" :style="{height: wh + 'px'}" class="right-scroll-view" scroll-y="true">
				<view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
					<view class="cate-lv2-title">/ {{item2.cat_name}} /</view>

					<!-- 动态渲染三级分类的列表数据 -->
					<view class="cate-lv3-list">
						<!-- 三级分类 Item 项 -->
						<view @click="gotoGoodsList(item3)" class="cate-lv3-item" v-for="(item3, i3) in item2.children"
							:key="i3">
							<!-- 图片 -->
							<image :src="item3.cat_icon"></image>
							<!-- 文本 -->
							<text>{{item3.cat_name}}</text>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	import badgeMix from '@/mixins/tabbar-badge.js'

	export default {
		mixins: [badgeMix],

		data() {
			return {
				wh: 0,
				active: 0,
				cateList: [],
				cateLevel2: []
			}
		},

		onLoad() {
			const sysInfo = uni.getSystemInfoSync()
			this.wh = sysInfo.windowHeight - 50

			this.getCateList()
		},

		methods: {
			async getCateList() {
				// 发起请求
				const {
					data: res
				} = await uni.$http.get('/api/public/v1/categories')
				// 判断是否获取失败
				if (res.meta.status !== 200) return uni.$showMsg()
				// 转存数据
				this.cateList = res.message

				this.cateLevel2 = res.message[0].children
			},

			activeChanged(i) {
				this.active = i

				this.cateLevel2 = this.cateList[i].children

				this.scrollTop = this.scrollTop ? 0 : 1
			},

			gotoGoodsList(item3) {
				uni.navigateTo({
					url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
				})
			},

			gotoSearch() {
				uni.navigateTo({
					url: '/subpkg/search/search'
				})
			}
		},
	}
</script>

<style lang="scss" scoped>
	.scroll-view-container {
		display: flex;

		.left-scroll-view {
			width: 120px;

			.left-scroll-view-item {
				line-height: 60px;
				background-color: #f7f7f7;
				text-align: center;
				font-size: 12px;

				// 激活项的样式
				&.active {
					background-color: #ffffff;
					position: relative;

					// 渲染激活项左侧的红色指示边线
					&::before {
						content: ' ';
						display: block;
						width: 3px;
						height: 30px;
						background-color: #c00000;
						position: absolute;
						left: 0;
						top: 50%;
						transform: translateY(-50%);
					}
				}
			}
		}
	}


	.cate-lv2-title {
		font-size: 12px;
		font-weight: bold;
		text-align: center;
		padding: 15px 0;
	}


	.cate-lv3-list {
		display: flex;
		flex-wrap: wrap;

		.cate-lv3-item {
			width: 33.33%;
			margin-bottom: 10px;
			display: flex;
			flex-direction: column;
			align-items: center;

			image {
				width: 60px;
				height: 60px;
			}

			text {
				font-size: 12px;
			}
		}
	}

	.search-box {
		// 设置定位效果为“吸顶”
		position: sticky;
		// 吸顶的“位置”
		top: 0;
		// 提高层级，防止被轮播图覆盖
		z-index: 999;
	}
</style>
